Investigation of Magnetic Phase Transitions in Spinel Cobalt Vanadate Thin Films using XAS and XMCD

Epitaxial thin films of cobalt vanadate spinels have been successfully grown on SrTiO₃ (001) substrates. Due to an in-plane compression of the unit cell, previous magnetization studies via neutron scattering^1,2 and torque magnetometry³ show a 90 K magnetization reorientation from out-of-plane to in-plane that is not present in bulk crystals of CoV₂O₄. To elucidate the nature of this phase transition, the L_3,2 edge is investigated using soft X-ray Absorption Spectroscopy (XAS) and X-ray Magnetic Circular Dichroism (XMCD). In this talk, we review the XAS and XMCD data of Cobalt Vanadate thin films and share how the magnetic reorientation affects the XAS and XMCD data on both the Cobalt and Vanadium sites.

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2. Thompson, C. J. et al. Spin canting and orbital order in spinel vanadate thin films. Phys. Rev. Mater. 2, (2018).

3. Kim, S., et.al. Large magnetic anisotropy and magnetostriction in thin films of CoV₂O₄. Phys. Rev. Materials, 7(1), 24–26. (2023)